<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			//顺序为1/1  2/2  3/4   4/7  5/11，分母为前一项分子分母的和，分子为123456
			function computed(n) {
				let i = 1; //分子为i,分母为j,同时用i来做标记
				let j = 1;
				while(i < n){
					j = i + j;
					i++;
				}
				return `${i}/${j}`
			}
			console.log(computed(5));
		</script>
	</body>
</html>
